wonder if there is a way to put a low voltage to run through case to "shock" would-be thieves... with a non conductive shield for the main components.

i.e. someone tries to open case to grab a part, they get a shocking welcome....
just enough juice to let them know they are alive, ya'know? With something like a battery backup incase the psu gets unplugged?

That's what I will be doing when I go to college next year. I'll be buying some heavy duty 1" steel wire, chains, multiple padlocks, etc. I will also be buying a fairly large full tower chassi (most likely a 800D or something along the lines) and bolting it to the ground. I'll be attaching the chassi to my table and bed frame with chains and padlocks.

Sure, it might take me 2 hours just to change a case fan, but at least it will make it that much harder for the robber to steal it.